The present invention relates generally to apparatuses for mixing fluids, such as paints, for example, in containers placed in bucket-type receptacles on such mixing apparatuses, and more particularly to buckets adapted to selectively receive containers of different shapes and to register such containers in properly balanced positions.
Paints or other fluids are typically mixed or blended into homogenous mixtures while in the same cylindrical containers in which they are shipped, stored, sold, and ultimately dispensed by the user. An example of the need for such in-container mixing results from colorants or pigments being added to base paints. In order to properly position and restrain these cylindrical containers, the mixing apparatuses typically include cylindrical receptades or “buckets” into which the containers are inserted. Such cylindrical buckets are frequently mounted and positioned on their mixing apparatuses for balanced spinning or rotating motion about the mixing apparatuses' rotation axes, which extend internally through the centers of the bases of these buckets, and for simultaneous “planetary” revolution about external revolution axes that may or may not be parallel to the internal rotation axes. Such cylindrical buckets can also be mounted and positioned on their mixing apparatuses for other balanced motion about the other mixing apparatuses' motion axes, which also extend internally through the buckets.
The typical paint cylindrical container has its “central geometric axes” extending perpendicularly through the center of its circular base such that the radially outer periphery of the cylindrical container is geometrically symmetrical with respect to such central geometric axis. Such a container also has an internal “center of gravity axis” extending through the container's center of gravity and about which the container is balanced when rotated. Because the container is symmetrical, the central geometric axis and the center of gravity axis are coincident and colinear. Therefore, such cylindrical containers are properly balanced when received within the correspondingly cylindrical buckets described above because their center of gravity axes are properly aligned and colinear with the rotation axes of the mixing apparatuses.
Recently, however, at least one paint manufacturer has introduced a paint can or container that is non-cylindrical, with a substantially square lateral cross-sectional shape and radiused corners. This so-called “square container” also has a partial cut-out handle portion at one corner to form an integral handle at an intermediate longitudinal height between the container's base portion and top portion. Because of this configuration with its handle and cut-out portion, and the resultant lateral displacement of paint, the square container's center of gravity does not lie on its central geometric axis. This results in its center of gravity axis being laterally or radially offset relative to its central geometric axis which extends perpendicularly through the center of its substantially square base and is laterally centered with respect to the laterally outer confines of the space occupied by the square container. Thus, such a square container typically cannot be received within the conventional cylindrical bucket of a mixing apparatus. Even if the bucket's shape was changed to a square lateral cross-section, the square container would be rotationally unbalanced if its central geometric axis were coincident and colinear with the rotation axis of the conventional cylindrical bucket. Such weight imbalance would result in damage, or at least undue and premature wear, to the motion transmission mechanisms and components of the mixing apparatus.
In order to accommodate both the conventional cylindrical containers and the new square containers, the above-described mixing apparatuses would have to be equipped with interchangeable conventional cylindrical buckets and “square buckets”, each appropriately shaped and configured to properly align its corresponding container's center of gravity axis with the rotation axis of the mixing apparatus. In addition, besides duplicating bucket costs and resulting in undue inconvenience in the storage of multiple buckets, such an arrangement would require either the provision of multiple mixing apparatuses at a given site or the inordinately time-consuming dismounting of one bucket and re-mounting of another bucket each time a single mixing apparatus is to be used for a container having a shape and configuration different from that of the container for which the mixing apparatus was last used.
The present invention seeks to over come these disadvantages by providing a single mixing apparatus bucket that is adapted to receive and restrain either cylindrical containers or non-cylindrical containers and that properly registers either of such containers so that its center of gravity axis is colinearly aligned with the rotation axis of the bucket and the mixing apparatus.
According to the present invention, an adapter bucket is provided for a mixing apparatus for mixing a fluid in a fluid container, with the mixing apparatus including a motion axis about which the container is moved by the mixing apparatus. The adapter bucket is mountable on the mixing apparatus for receiving and restraining either a first container having its center of gravity axis coincident with its central geometric axis or a second container having its center of gravity axis offset with respect to its central geometric axis. The adapter bucket preferably includes a generally cup-shaped body for receiving said selected container therein, with the body including a base through which the motion axis of the mixing apparatus extends when said adapter is mounted on the mixing apparatus and a number of adapter sides extending or protruding transversely, upwardly from the base. The selected container is positioned with its center of gravity axis along the apparatus' motion axis when the selected container is received within the adapter between the adapter sides regardless of whether the selected container is the first container or the second container.
The adapter bucket is especially well adapted for accommodating situations where the above-mentioned first container has a generally circular lateral cross-sectional shape with a generally cylindrical first container side, and the second container has a generally polygonal lateral cross-sectional shape with a number of substantially straight container sides. Preferably internal partial walls or tabs protruding transversely, generally upwardly, from the base of the adapter bucket act as restraining members to tangentially engage and laterally restrain the first (cylindrical) container when the first container is received within said adapter, and spring dips or pivotal tabs restrain the container vertically. A number (only two in the exemplary embodiment described herein) of the adapter bucket's upwardly protruding sides generally flatly engage and act as restraining members to laterally restrain the second (“square”) container's sides when the second container is received within said adapter, with the other two of the adapter bucket's sides preferably being spaced apart from a corresponding or adjacent pair of the second container's sides when the second container is received within the adapter bucket
In the preferred exemplary embodiment described herein, the adapter bucket includes an intermediate adapter bucket side or corner interconnecting the adapter bucket sides that are spaced apart from the second container sides, with this intermediate side or corner portion tangentially engaging a portion (preferably a corner portion) of the second container when the second container is received within the adapter bucket. In the preferred, exemplary embodiment described herein, this is accomplished by way of this intermediate side or corner portion of the adapter bucket being formed as a radiused corner having a larger (and therefore shallower) radius than the other three radiused corners of the adapter bucket. This results in the spaced apart adapter bucket sides and the central geometric axis of the second container being on opposite sides of the motion (rotation) axis of the bucket (and thus of the mixing apparatus) when the second (“square”) container is received in its offset position within the adapter bucket.
Because of this unique configuration, a conventional fluid container can be inserted into the adapter bucket and be properly centered, aligned and balanced for mixing, as usual in the prior art. However, according to the present invention, the same bucket (called the “adapter” or “adapter bucket” herein) can also interchangeably accommodate the non-conventional so-called “square containers,” with their cut-out handle portions at one side or one corner laterally displacing a portion of the fluid in the container and thus shift its center of gravity axis laterally away from its central geometrical axis. The adapter bucket of the present invention urges the non-cylindrical container in a lateral direction, as mentioned above, generally towards the cut-out handle portion in order to colinearly align the container's center of gravity axis with the rotation axis of the bucket and the mixing apparatus and properly balance the container. This lateral shifting is accomplished as a result of the larger radiused corner of the adapter bucket having a larger radius than that of the other three corners, as described above, and tangentially engaging a radiused corner on the so-called square container to cause the square container to be shifted laterally in a direction toward the container's cut-out handle portion, thus compensating for the lateral difference between the square container's central geometrical axis and its center of gravity axis.
Preferably, visual or other indicators are provided on the adapter bucket in order to allow the user to properly orient the square container when inserting it into the adapter bucket so that the center of gravity axis of the container can be properly aligned colinearly with the rotation axis of the mixing apparatus. In addition, other orienting configurations can be included on the adapter bucket, such as one or more laterally inwardly protruding “dimples” or other protrusions from its sides so that such protrusion can engage the cut-out portion of the square container. Still other well known orienting, registering or “detent” features will occur to those skilled in the art to assure proper insertion of the or other non-cylindrical containers that have a center of gravity axis offset relative to their central geometrical axes.
Other objects, advantages and features of the present invention, in addition to those examples mentioned above, will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings.